1. Field of the Invention
This invention relates to the material-removing working of hard or soft tissues of the human or animal body or artificial parts thereof; and more particularly it concerns novel tools and instruments for such working.
2. Description of the Related Art
For the material-removing working of hard or soft tissues of the human or animal body or artificial parts thereof, such as e.g. protheses, there are already known various instruments and associated tools. Here, there may be involved both tools for a surface treatment and also tools for the making of a cavity or parting-off tools. Basically, one can divide the working movements of a tool of the kind being considered and associated instruments with drives into three groups, namely rotational movements, longitudinal movements and oscillation movements. A rotation movement takes place with conventional drills or millers and with circular saws. Longitudinal movements are employed for surface working, such as is the case with files, whereby the surface working may take place in a cavity, e.g. in a root canal, or at an outer surface, e.g. at the surface of a tooth or bone. Combinations of the above-mentioned movements are also possible and have also already been proposed for instruments and tools for the preparation of tooth root canals. A particular working movement is an oscillating movement, which may involve both a longitudinal movement, an orbital movement in a plane, e.g. orbital movements along a circular or elliptical path, or a three-dimensional movement. Significant features of such an oscillation movement are a high frequency and small amplitude.
Instruments and tools of the last mentioned kind are described for medical purposes in WO 96/14024.